Terry, I have a 03 Lazer Z with the 23 Kohler. The last two times I ran it after I engage the blades the engine RPM's Fall off after a couple of minutes of running time. The last time it would vary RPM's at diffent times while I finish cutting the yard. I would think that it is something with the Governor. I will probably bring it back to 4-H Equipment in the next couple of weeks for them to check it out unless you know of some simple fix for this. It has about 60 hours of time on it. ??? Any thoughts ?